We show how the combination of the spatial autocorrelation function and permeability calculations, applied to 3D X-ray computed tomography data, can yield quantitative information on the anisotropy of both meso-structure and fluid flow in Diesel Particulate Filter (DPF) materials, such as Cordierite and SiC. It was found that both the degree of anisotropy, and the orientation of the permeability and meso-structure are similar, but not identical. We confirm that the morphological anisotropy of cordierite materials is weak, and clearly influenced by the extrusion process that determines the main direction of anisotropy. Properties of the autocorrelation function are discussed and it is shown why estimating the characteristic length of real meso-structures (grain or ‘pore’ size) is not possible. Finally, we show that the autocorrelation function applied on grey-level images can give a good estimate of the degree of anisotropy even with limited resolution.

我们展示了如何将空间自相关函数和渗透率计算相结合，应用于3D X射线计算机断层扫描数据，可以产生有关柴油微粒过滤器（DPF）材料中介观结构和流体流动各向异性的定量信息，例如堇青石和SiC。发现各向异性程度，磁导率和介观结构的取向相似，但不相同。我们确认堇青石材料的形态各向异性很弱，并且明显受到决定各向异性主要方向的挤压过程的影响。讨论了自相关函数的属性，并说明了为什么无法估计实际介观结构的特征长度（晶粒或“孔”的大小）是不可能的。最后，